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impl Hash for Value when "preserve_order" feature is not set #1127

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impl Hash for Value when "preserve_order" feature is not set #1127

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edwardycl
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IndexMap is the only type that is used within Value that does not implement Hash, and it is by design: indexmap-rs/indexmap#288 (comment)

If "preserve_order" feature is not set, Value::Object uses BTreeMap instead of IndexMap so it is possible to auto-impl Hash for Value.

dtolnay
dtolnay reviewed Apr 25, 2024
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Cargo features are required to be additive, so enabling a feature cannot result in an impl being removed.

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edwardycl commented Apr 25, 2024 •
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Now that I think about it, since the type of key is fixed to String, IndexMap can also be hashed by sorting its key-value in a consistent order. It doesn't break the Eq-Hash relationship, and we can implement Hash regardless of the "preserve_order" feature. What do you think?

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